A spokesman said: “Patients who take medicines like Clozapine and Ranibizumab often have a higher risk of complications or death because of ­serious underlying health conditions.

“Clozapine is an ­effective anti-psychotic medication used to treat schizophrenia and severe thought disturbances in Parkinson’s patients.

“Clinical evidence shows the benefits of these medicines to ­patients outweigh the risks. We closely monitor the performance and side effects of these ­medicines and we will take the appropriate action if there is evidence they are unsafe for patients.

“All medicines have side effects. The fact an adverse reaction has been reported does not ­necessarily mean the medicine has been ­proven to cause the reaction.”